Search

Objectives The aim of this study was to evaluate the 3-dimensional images of thinner main peripheral vessels in oral and maxillofacial regions made without contrast medium by using a new technique, fresh blood imaging (FBI). A second objective was to discern arteries from veins by using the combination of FBI with the subtraction technique. Study design Images from FBI were compared with those from 3-dimensional phase-contrast magnetic resonance angiography (MRA) of blood vessels in 20 healthy subjects. All images were scored for visualization and image quality of the main blood vessels. In addition, appropriate flow-spoiled gradient pulses were applied to differentiate arteries from veins in the peripheral vasculature using a combination of FBI sequences and subtraction between systole- and diastole-triggered images. Results The scores of MRA using FBI for the visualization of thin blood vessels were significantly better than those using phase contrast, whereas scores for the visualization of main blood vessels were equal. Additionally, we succeeded in our initial attempt to differentiate arteries from veins with a reasonable acquisition time. Conclusions Our initial experience shows that FBI could be a useful method to identify 3-dimensional vasculature and to differentiate arteries from veins among thinner peripheral vessels in the oral and maxillofacial regions without using contrast medium.

Objective The aim of this study was to evaluate the effect of altering changing head and body positions on the 2- and 3-dimensional (3D) configuration of the oropharynx with jaw protrusion. Study design Twelve healthy individuals (8 male, 4 female) with no history of sleep disturbances were invited to participate. For each subject, an acrylic splint was made with the mandible in protruded position. Subjects were imaged using magnetic resonance imaging in 4 different jaw, head, and body positions: 1) supine without protrusion; 2) supine with jaw protrusion; 3) supine with head rotation and jaw protrusion; and 4) laterally recumbent position with jaw protrusion. The 2- and 3D images of the upper airway in different positions were reconstructed by using a free DICOM reconstruction software. The dimension changes (anteroposterior and lateral dimensions, cross-sectional area, and volume) of the oropharynx (divided into retropalatal region and retroglossal region) were calculated and analyzed. Statistical analyses were performed using the Bartlett test and 1-way analysis of variance with α = .05. Results Compared with nonprotruded position, dimensions of the oropharynx for both retropalatal region and retroglossal regions were found to be greater than with jaw protrusion. Head and body positions had little effect on configuration of the oropharynx with jaw protrusion in either 2- or 3D. The only change noted was a greater anteroposterior dimension of retropalatal region with head rotation and lateral supine position compared with the supine position. Conclusions Head and body positions have little effect on 2- and 3D airway dimensions on supine patients with jaw protrusion.

Objective The objective of this study was to evaluate the clinical significance of ultrasonography (US) for screening for thyroid gland diseases when surveying the cervical lymph nodes to detect metastasis in subjects with oral squamous cell carcinoma (SCC). Methods The detection rates and characteristics of abnormal thyroid findings detected by US in 301 subjects with oral SCC were analyzed. Subjects with abnormal findings were referred to thyroid specialists and the diagnoses and treatments from these specialists were noted. The ratio of subjects who consulted a thyroid specialist after indications of thyroid gland abnormalities to analyze subject compliance was also examined. Follow-up examinations were regularly conducted to assess any changes in the thyroid gland. Results Of the 301 subjects with oral SCC, 91 had abnormal thyroid gland findings on US. As subject age increased, the rate of detection of abnormal thyroid gland findings on US significantly increased. The rate of detection of abnormal findings in women by US was significantly higher than that in men, but the male-to-female ratio was lower compared with that in previous reports. It was demonstrated that oral SCC in the floor of the mouth was associated with the highest prevalence of abnormal findings in the thyroid gland (40%), followed by oral SCC of the maxillary gingiva (39%). Of the 91 subjects with abnormal findings, 10 showed enlargement in the size of the lesion on follow-up examination with US. Eleven subjects with no abnormal findings on initial examination showed abnormal findings on follow-up examination. Conclusion The results suggest that subjects with oral SCC have a relatively high rate of abnormal findings in the thyroid gland that can be detected by US. Scans that include the thyroid gland should be performed when surveying cervical lymph nodes for metastasis during US examination. Particular attention should be paid to thyroid gland–related diseases in older men who have oral cancer and to thyroid gland abnormalities if patients had oral SCC in the floor of the mouth or of the maxillary gingiva. It is recommended that follow-up US examinations be regularly performed in cases of oral SCC.

The aim was to evaluate the utility of dynamic magnetic resonance (MR) sialographic images as a diagnostic tool for patients with xerostomia as chief complaint.Various parameters of dynamic MR sialographic images from 40 healthy volunteers were compared with those from 28 patients having dry mouth as chief complaint. Dynamic MR sialographic images were acquired using a 1.5-T full-body MR system and 2-dimensional fast asymmetric spin-echo (2D-FASE) sequences. Acquisition of the optimal section using 2D-FASE sequencing with single-section acquisition of thick sections was repeated every 30 s before and after a few drops of 5% citric acid was placed on the tongue. Student t test was used to examine differences between the healthy volunteer and patient groups regarding the maximum area of salivary gland ducts before and after citric acid stimulation.The maximum area of the detectable ducts in the patient group was significantly smaller (P0.001), whereas the change in detectable duct area was significantly lower (P0.001).This study suggests that dynamic MR sialographic images and data can be useful in the diagnosis of patients with dry mouth as chief complaint.

Objective To evaluate a proposed technique for the 3-dimensional (3D) detection of hemangiomas, including vascular malformation and their feeding arteries, in the head and neck. The new technique combines phase-contrast magnetic resonance angiography (PCMRA) without contrast medium and 3D fast asymmetric spin-echo (FASE) sequences. Methods The technique was applied to 3 patients having hemangiomas in the head and neck region. In 1 patient the image obtained with the proposed technique was compared to that obtained by standard contrast angiography. Results In all 3 patients, the 3D presence of the hemangiomas and the feeding arteries were well defined in images created by the proposed technique. Additionally, the characterization of the hemangioma's 3D structure and distribution of the feeding arteries coincided with those observed using contrast angiography in the case for which contrast angiography was also performed. Conclusions Preliminary experience shows that the proposed technique combining 3D-FASE and 3D-PCMRA is useful to visualize both the 3D structure of hemangiomas and to identify the 3D distribution of the feeding arteries without using contrast medium.

Objective To evaluate the utility of magnetic resonance (MR) cisternography using 3-dimensional (3D) fast asymmetric spin-echo (FASE) sequences with multiplanar reconstruction (MPR) for detection of the sites of neurovascular compression (NVC) in patients with trigeminal neuralgia. Study design Both MR cisternography with 3D-FASE sequences and MR angiography (MRA) were performed on 150 patients with clinical signs and symptoms that suggested trigeminal neuralgia. Results from the original MR cisternography with 3D-FASE sequences, the original MRA, and 4 reformatted images were used for interpretation. Images with inversion between black and white were used from the MR cisternography with 3D-FASE sequences to evaluate NVC. A diagnosis of NVC was made from the presence of vascular contact with the trigeminal nerve at the root entry zone (REZ) and the nature of the involved vessels. For the patients with NVC detectable on 3D-FASE or MRA images, the relationship between the clinically manifested regions and the NVC sites was also evaluated. Results Of the 150 patients evaluated, 89 were deemed to have NVC. Of these 89 patients, 3 underwent surgery that identified the artery that was involved with the trigeminal nerve. The correlation between the clinically manifested regions and the NVC sites was significantly detectable using both 3D-FASE images and MRA in 89 patients with detectable NVC. The correlation coefficient using 3D-FASE imaging was a little higher than that using MRA. Of the 61 patients deemed not to have NVC, 6 were found to have brain tumors that invaded the root entry zone of the trigeminal nerve. However, the remaining 55 patients had no identifiable cause for trigeminal neuralgia. NVC was found in the asymptomatic side in 27 (18%) of the 150 patients with trigeminal neuralgia using MR cisternography with 3D-FASE sequences. Conclusions The technique of MR cisternography using 3D-FASE sequences with MPR is more accurate and useful than MRA for detection of the site of NVC in patients with trigeminal neuralgia. Patients with trigeminal neuralgia should be further examined using MR imaging to rule out a brain tumor. Radiologists should understand that a few subjects with no symptoms could show NVC with MR cisternography.

Objective In a previous study, we named the magnetic resonance imaging (MRI) signal that is characteristic of mandibular condyles in growing children the “double contour-like structure” (DCLS). In the current study, we evaluated the alternating appearance and disappearance of the DCLS in children as they grow to elucidate the significance of the DCLS. Study design In 11 subjects who were 9-14 years old at the time of the first examination, MRI characteristics of mandibular condyles were sought from fast spin-echo intermediate-weighted images; 2 or 3 years later, repeat MRI were obtained from the same subjects. Results At the second examination, 10 of the 16 DCLSs detected at the first examination had disappeared. A significant relationship was found between the alternation of the DCLS and the bone marrow conversion from red to yellow in mandibular condyles. Alternation of the DCLS tended to coincide with eruption of the permanent maxillary second molars. The DCLS was also shown to appear as a hypersignal on T2-weighted images. Conclusions Double contour-like structure signals in mandibular condyles appeared and disappeared as children grew, and these signal alternations may be useful as a criterion for the staging of mandibular condyle development in children. Possible constituents of the DCLS may be hypervascular loose fibrous tissue and a proliferation of cartilage.

Objectives We investigated the occurrence of inflammatory paradental cysts (IPC) in the mandibular premolar, and demonstrated the points of difference with regard to diagnostic features between IPC and dentigerous cysts (DC). Material and methods We analyzed the radiographs and histology of 60 cases with a cystic lesion associated with inflammation in the mandibular premolar region based on diagnostic criteria as IPC. Results In 4 out of 60 cases, we diagnosed the 4 cysts as IPCs in the mandibular premolar region, and recognized that one form of IPC was similar to a mandibular infected buccal cyst. The other 56 non-IPC cases were diagnosed as DC. On the IPCs, the permanent tooth normally erupted in all 4 cases after treatment, but in one case, the IPC recurred. Conclusions The present investigation suggested that we might have misdiagnosed IPCs in the mandibular premolar region as DC to date. It is important to consider the differences between IPC and DC with regard to the causes of recurrence during treatment of IPC.

Objective We sought to determine the magnetic resonance imaging (MRI) characteristics of mandibular condyles in still-growing children. In addition, we also evaluated the significance of the double-contour–like structure and the conversion from red to yellow marrow characteristic of this age. Methods The MRI characteristics of mandibular condyles were determined by means of fast spin-echo intermediate-weighted images in subjects 9 to 14 years old. In 1 subject who developed temporomandibular joint–related clinical symptoms 1 year later, MRI was re-performed at that time. Results With the use of MRI, a total of 17 double-contour–like structures were detected in 42 temporomandibular joints of 9- to 14-year-olds, but neither 50 healthy joints of youths nor adults. In terms of bone marrow signal changes, the turning point was found to be 11 years old. In 1 subject, the double-contour–like structures were not visible on the MR images obtained 1 year after the first examination. Conclusion The double-contour–like structure and the periods of conversion from red to yellow marrow may be able to be used as part of the criteria for the staging of mandibular condyle development in children.